Hi Mateen - are you using the cloud or on-premise solution? I know in the on-premise version this field is ignored by the catalog filter coe, but you can write your own custom filter to evaluate on this field.
Here's what the Catalog Format Reference Guide says about Terrotory Available:
Use the Territory Available field and ISO 3166-1 or 3166-2 territory codes to display certain catalog items
to specific users based on geography. Users who reside outside of the countries or regions listed cannot see
that item. Catalog items with no Territory Available field appear to all users.
Note: Ariba procurement solution ignores the Territory Available field by default. However, buying
organizations can write custom filters to enable the field in Ariba procurement solution. Contact your
customers to find out whether they have configured their procurement applications to use this field, and
which code standard they use.
Do not use these ISO codes to specify currency or language. For more information, see Currency on
page 29 and Language on page 73.
Territory Available Field Description:
List of one or more ISO country or region codes. Ariba
recommends that you use ISO 3166-1 and 3166-2 codes for this
field. If there is more than one code, separate them with commas
and quote the entire field.
This string is case-insensitive.